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1.Data driven structural damage assessment approach by the twin of Bayesian theory non-homogeneous Poisson process

Author:Zhu Lin;Chen Min;Jia Minping;Feng Yuegui;Qing Guangwei

Source:Journal of Vibration Engineering,2021,Vol.34

Abstract:A damage assessment approach for structure by twin Bayesian theory for non-homogeneous Poisson process is proposed,in which the damage for structure in the crack propagation is selected as the object.The prior parameter distribution for different damage situation is obtained by combine the reliability sequencing strategy based on crack tip field energy with the non-homogeneous Poisson model,and having an effective integration on the test information with the gradual relation by using Bayesian method.At the same time,the posterior distribution calculation approach based on Bayesian is achieved by using the prior information,based on the progressive factor of crack tip field energy and the likelihood function.Furthermore,the typical structure is selected as a case study.The evaluation results are compared with the test results.It can be clearly found from the results that the average accuracy of the proposed approach is 92.1%%,and this approach can be used to complete the purpose of damage assessment by using a small amount of test information.

2.Approach for structural health assessment based on the Bayesian theory

Author:Zhu Lin;Chen Min;Jia Minping

Source:Journal of Vibration and Shock,2020,Vol.39

Abstract:The structural health assessment in the crack propagation process was studied.Considering the wide existence of Weilbull distribution data characteristics in the assessment process,an approach for structural health assessment based on the Bayesian theory was proposed through combining the data of the type of Weibull distribution with the Bayesian theory.The numerical solutions for the complex posterior problems were provided by using the MCMC algorithm.The acoustic emission approach was adopted to collect the health assessment data for an industrial component.The health result obtained by the proposed model shows that two fractile parameters of 5%% and 95%% constitute the 90%% of confidence interval of the assessment parameter for structural health.The posterior parameters are centrally distributed and the confidence level is up to 90%%,which verifies the accuracy of the health assessment method.

3.Discussion mechanism based brain storm optimization algorithm

Author:Yanh Yuting;Shi Yuhui;Xia Shunren

Source:Journal of Zhejiang University. Engineering Science,2013,Vol.47

Abstract:A discussion mechanism based brain storm optimization (DMBSO) algorithm was proposed in order to solve the problem that brain storm optimization (BSO) algorithm is likely to stagnate in the local optima and result in premature convergence. DMBSO used a new mechanism with inter-group discussion and intra-group discussion to replace the process of individual updating in the original BSO algorithm in order to respectively govern the ability of global search and local search. The ability of global search was enhanced at the beginning by linearly decreasing times of inter-group discussion and increasing times of intra-group discussion, while fine search was enhanced in the end to prevent premature convergence. Empirical studies were conducted to evaluate the performances of the DMBSO algorithm for the 10D, 20D, 30D problems of six popular benchmark functions (BFs). Experimental results demonstrate that the DMBSO algorithm can avoid being stagnated in the local optima, more effectively and steadily find the better results than the original BSO algorithm and standard particle swarm optimization (PSO) algorithm, and show stronger robustness with the increasing of BFs dimension.

4.A new method for evaluating small-strain shear modulus of sandy soils based on binary medium model

Author:Wu, Q;Liu, K;Guo, QZ;Zhao, K;Chen, GX

Source:ROCK AND SOIL MECHANICS,2020,Vol.41

Abstract:To investigate the effect of initial effective consolidation stress sigma(co), void ratio e, and fines content FC on the small-strain shear modulus G(max) of saturated sandy soils, a series of isotropically consolidated bender element tests is performed on three saturated sandy soils with various physical properties. The test results show that the stress exponent n, reflecting the rate of G(max), increment due to the enhancement of sigma'(co), presents a soil-specific constant, and there is a good exponential correlation between n and the synthesizing grain size distribution parameter C-u(s)center dot C-u(f) of sandy soils. Fitting parameter A of Hardin model decreases as FC increases, and an exponential correlation is found. But there is no obvious single correlation between fitted parameter d and FC. Combined with the test data of G(max) of three saturated sandy soils in the literature, it is found that the stress-corrected small-strain shear modulus G(max)/(sigma'(co)/P-a)(n) for different types of sandy soils decreases monotonically with the increase of the equivalent skeleton void ratio e(sk)(center dot), and a good power relationship between G(max)/(sigma'(co)/P-a)(n) and e(sk)(center dot) is then obtained. Generalized Hardin model that allows unified characterization of G(max) values for different types of sandy soils with various sigma'(co), e and FC is established based on binary medium model.

5."Parallel-Tempering"-Assisted Hybrid Monte Carlo Algorithm for Bayesian Inference in Dynamical Systems

Author:Sun, SJ;Shen, Y

Source:ADVANCES IN COMPUTATIONAL INTELLIGENCE SYSTEMS (UKCI 2019),2020,Vol.1043

Abstract:The aim of this work is to tackle the problem of sampling from multi-modal distributions when Hybrid Monte Carlo (HMC) algorithm is employed for performing Bayesian inference in dynamical systems. Hybrid Monte Carlo is a powerful Markov Chain Monte Carlo (MCMC) algorithm but it still suffers from the "multiple peaks" problem. Due to non-trivial structure in the space of (a class of) dynamical systems, posterior distribution of its model parameters could exhibit complicated structures such as multiple ridges. We examined a MCMC algorithm combining HMC with so-called Parallel Tempering (PT) - a well-known strategy for tackling the problem highlighted above. The new algorithm is referred to as PT-HMC. Our numerical experiment demonstrated that when compared to the ground truth, the posterior distributions derived from PT-HMC samples is more accurate than those from HMC.

6.In their shoes A structured analysis of job demands, resources, work experiences, and platform commitment of crowdworkers in China    

Author:Wang, Yihong ; Papangelis, Konstantinos ; Lykourentzou, Ioanna ; Liang, Hai-Ning ; Sadien, Irwyn ; Demerouti, Evangelia ; Khan, Vassilis-Javed

Source:Proceedings of the ACM on Human-Computer Interaction,2020,Vol.4

Abstract:Despite the growing interest in crowdsourcing, this new labor model has recently received severe criticism. The most important point of this criticism is that crowdworkers are often underpaid and overworked. This severely affects job satisfaction and productivity. Although there is a growing body of evidence exploring the work experiences of crowdworkers in various countries, there have been a very limited number of studies to the best of our knowledge exploring the work experiences of Chinese crowdworkers. In this paper we aim to address this gap. Based on a framework of well-established approaches, namely the Job Demands-Resources model, the Work Design Questionnaire, the Oldenburg Burnout Inventory, the Utrecht Work Engagement Scale, and the Organizational Commitment Questionnaire, we systematically study the work experiences of 289 crowdworkers who work for ZBJ.com - the most popular Chinese crowdsourcing platform. Our study examines these crowdworker experiences along four dimensions (1) crowdsourcing job demands, (2) job resources available to the workers, (3) crowdwork experiences, and (4) platform commitment. Our results indicate significant differences across the four dimensions based on crowdworkers' gender, education, income, job nature, and health condition. Further, they illustrate that different crowdworkers have different needs and threshold of demands and resources and that this plays a significant role in terms of moderating the crowdwork experience and platform commitment. Overall, our study sheds light to the work experiences of the Chinese crowdworkers and at the same time contributes to furthering understandings related to the work experiences of crowdworkers. © 2020 Copyright held by the owner/author(s). Publication rights licensed to ACM.

7.Scientific research into designing, while doing justice to designing

Author:Fischer, T

Source:ARCHITECTURAL SCIENCE REVIEW,2014,Vol.57

Abstract:This paper outlines some interests shared by cybernetics and design research that are incompatible with the ideals of natural science. The experimental design of an ongoing research-into-design study is presented, which aims to bridge the aforementioned incompatibility. The study investigates the degree of congruency between perceptions of "creative direction-giving" between collaborating designers. Pilot study results indicate low congruencies, possibly due to designers' lack of sensitivity towards their team dynamics. The methods applied in this study were chosen and developed to accommodate both the (design) cybernetic and natural science perspective.

8.Mutual relationships of suspended sediment, turbidity and visual clarity in New Zealand rivers

Author:Ballantine, DJ;Hughes, AO;Davies-Colley, RJ

Source:SEDIMENT DYNAMICS FROM THE SUMMIT TO THE SEA,2014,Vol.367

Abstract:Many river water quality monitoring programmes do not measure suspended particulate matter (SPM) mass concentrations despite significant interest in its multiple effects on aquatic ecosystems. Regular monthly sampling usually intercepts rivers in baseflow when suspended sediment mass concentrations and fluxes are relatively low and not of particular interest. New Zealand's National Rivers Water Quality Network (NRWQN) is probably typical in not measuring SPM mass, although visual clarity and nephelometric turbidity are routinely measured. In order to better characterize SPM in NZ rivers, total suspended sediment (TSS) was temporarily added to the NRWQN. Turbidity, visual clarity and TSS are mutually inter-related over all 77 sites, although with considerable data scatter. However, within individual rivers turbidity and visual clarity are typically fairly closely related to TSS and provide fair to excellent surrogates. Therefore, TSS need not be measured routinely because it can be estimated with sufficient precision for many purposes from visibility or turbidity.

9.trumpet: transcriptome-guided quality assessment of m(6)A-seq data

Author:Zhang, T;Zhang, SW;Zhang, L;Meng, J

Source:BMC BIOINFORMATICS,2018,Vol.19

Abstract:Background: Methylated RNA immunoprecipitation sequencing (MeRIP-seq or m(6)A-seq) has been extensively used for profiling transcriptome-wide distribution of RNA N6-Methyl-Adnosine methylation. However, due to the intrinsic properties of RNA molecules and the intricate procedures of this technique, m(6)A-seq data often suffer from various flaws. A convenient and comprehensive tool is needed to assess the quality of m(6)A-seq data to ensure that they are suitable for subsequent analysis. Results: From a technical perspective, m(6)A-seq can be considered as a combination of ChIP-seq and RNA-seq; hence, by effectively combing the data quality assessment metrics of the two techniques, we developed the trumpet R package for evaluation of m(6)A-seq data quality. The trumpet package takes the aligned BAM files from m(6)A-seq data together with the transcriptome information as the inputs to generate a quality assessment report in the HTML format. Conclusions: The trumpet R package makes a valuable tool for assessing the data quality of m(6)A-seq, and it is also applicable to other fragmented RNA immunoprecipitation sequencing techniques, including m(1)A-seq, CeU-Seq, psi-seq, etc.

10.Multimedia augmented m-learning Issues, trends and open challenges

Author:Yousafzai, Abdullah ; Chang, Victor ; Gani, Abdullah ; Noor, Rafidah Md

Source:International Journal of Information Management,2016,Vol.36

Abstract:The advancement in mobile technology and the introduction of cloud computing systems enable the use of educational materials on mobile devices for a location- and time-agnostic learning process. These educational materials are delivered in the form of data and compute-intensive multimedia-enabled learning objects. Given these constraints, the desired objective of mobile learning (m-learning) may not be achieved. Accordingly, a number of m-learning systems are being developed by the industry and academia to transform society into a pervasive educational institute. However, no guideline on the technical issues concerning the m-learning environment is available. In this study, we present a taxonomy of such technical issues that can impede the life cycle of multimedia-enabled m-learning applications. The taxonomy is devised based on the issues related to mobile device heterogeneity, network performance, content heterogeneity, content delivery, and user expectation. These issues are discussed, along with their causes and measures, to achieve solutions. Furthermore, we identify several trending areas through which the adaptability and acceptability of multimedia-enabled m-learning platforms can be increased. Finally, we discuss open challenges, such as low complexity encoding, data dependency, measurement and modeling, interoperability, and security as future research directions. © 2016 Elsevier Ltd. All rights reserved.

11.Design, analysis, tools and applications for programmable high-speed and power-aware 4G processors

Author:Man, Ka Lok ; Lei, Chi-Un ; Ma, Jieming ; Wu, Yanyan ; Guan, Sheng-Uei ; Jeong, T.T. ; Seon, J.K. ; Lee, Yunsik

Source:2011 International SoC Design Conference, ISOCC 2011,2011,Vol.

Abstract:Data rate traffic and communication capacity demand have been increased continuously. Therefore, a highly advanced 4G wireless system is required to meet a high demand for modern mobile terminals. For getting a further improvement for 4G communication systems, new paradigms of design, analysis tools and applications for 4G communication processors are necessary. In this paper, some of these new paradigms are discussed. Furthermore, a single-step discrete cosine transform truncation (DCTT) method is proposed for the modeling-simulation in signal integrity verification for high-speed communication processors. ©2011 IEEE.

12.Acrylonitrile-butadiene-styrene colored with a nanoclay-based filler: mechanical, thermal and colorimetric properties

Author:Xia, T;Ye, Y;Qin, WL

Source:POLYMER BULLETIN,2019,Vol.76

Abstract:Talc is a potential filler for enhancing mechanical and thermal performance of polymers. In this study, a novel kind of filler based on black talc and dye (Direct contact 28) was synthesized and characterized. The stained black talc was filled into acrylonitrile-butadiene-styrene at different content levels, and their mechanical, thermal and colorimetric properties were investigated. Furthermore, samples filled with talc were prepared in the same way. The particle size of stained black talc located both within and at the interface of acrylonitrile-butadiene-styrene was larger than that of the talc which was ascribed to agglomeration. As black talc can increase toughness and strength of acrylonitrile-butadiene-styrene in low filler loading, and the dye can improve compatibility between black talc and acrylonitrile-butadiene-styrene, so mechanical and thermal properties of stained black talc/acrylonitrile-butadiene-styrene have been enhanced. Within a certain amount of filler loading, acrylonitrile-butadiene-styrene can be colored by stained black talc, and its color deepened as filler loading increased. However, it can absorb part of incident light as some filler existed in the form of solid particles in acrylonitrile-butadiene-styrene matrix, which led to acrylonitrile-butadiene-styrene dimmed with increment of filler loading. This filler achieved modification, filling, enhancement and colorability; the optimum filler concentrations were less than 10wt%%. This study opens a new approach to utilizing black talc and to fabricating polymer fillers.

13.Sedenions, the Clifford algebra C`(8), and three fermion generations

Author:Gresnigt, Niels G.

Source:Proceedings of Science,2019,Vol.364

Abstract:Recently there has been renewed interest in using tensor products of division algebras, together with their associated Clifford algebras, to identify the structures of the Standard Model. One full generations of leptons and quarks transforming correctly under the electrocolor group SU(3)c U(1)em can be described in terms of complex octonion algebra C O. By going beyond the division algebras, and considering the larger Cayley-Dickson algebra of sedenions S, this one generation model is extended to exactly three generations. Each generation is contained in an C O subalgebra of C S, however these three subalgebras are not independent of one another. This three generation model can be related to an alternative model of three generations based on the exceptional Jordan algebra J3(O). It is speculated that the shared C H algebra common to all three generations might form a basis for CKM mixing. © Copyright owned by the author(s) under the terms of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License (CC BY-NC-ND 4.0).

14.Performing the Digital Self: Understanding Location-Based Social Networking, Territory, Space, and Identity in the City

Author:Papangelis, K;Chamberlain, A;Lykourentzou, I;Khan, VJ;Saker, M;Liang, HN;Sadien, I;Cao, T

Source:ACM TRANSACTIONS ON COMPUTER-HUMAN INTERACTION,2020,Vol.27

Abstract:Expressions of territoriality have been positioned as one of the main reasons users alter their behaviors and perceptions of spatiality and sociality while engaging with location-based social networks (LBSN). Despite the potential for this interplay to further our understanding of LBSN usage in the context of identity, very little work has actually been done toward this. Addressing this gap in the literature is one of the chief aims of the article. Drawing on an original 6-week study with 42 participants utilizing a bespoke LBSN entitled "GeoMoments," our research explores the following: (1) the way that territoriality is linked to self-identity; and (2) how this interplay affects the interactions between users as well as the environments they inhabit. Our findings suggest that participants affirmed their self-identity by selectively posting and claiming ownership of their neighborhood through the LBSN. Here, the locative decisions are made related to risk, hierarchies, and the users' relationship to the area. This practice then led participants to discover and interact with the digital information overlaying their physical environments in a playful manner. These interactions demonstrate the perceived power structures that are facilitated by identity claims over a virtual area. In the main, our results reaffirm that territoriality is a central concept in understanding LBSN use, while also drawing attention to the temporality involved in user-to-user and user-to-place interactions pertaining to physical place mediated by LBSN.

15.Simultaneous effects of pressure, temperature, impurity location, SOI and magnetic field on THG of a pyramid quantum dot

Author:Avazzadeh, Z;Bahramiyan, H

Source:OPTICAL AND QUANTUM ELECTRONICS,2020,Vol.52

Abstract:We have investigated simultaneous effects of pressure, temperature, impurity location, Rashba and Dresselhaus spin-orbit interaction and magnetic field on THG of realized GaAs/Al0.5Ga0.5As pyramid quantum dot with considering the wet layer. For this purpose, we have calculated the energy levels and wave function of one electron that is confined in constant potential, in presence of impurity, magnetic field, Rashba and Dresselhous SOI in various temperatures, pressure and impurity location in effective mass approximation by FEM. In the following, we have presented the effect of magnetic field, Rashba and Dresselhous SOI, temperature, pressure and impurity location on THG in various conditions. Results show that: (1) THG increases by increasing the magnetic field and the distance between the peaks decrease. Also, the peak corresponding to the E-21 transition has a blue shift and the peaks corresponding to the E-31/2 and E-41/3 transitions have a red shift. (2) THG decreases and shifts to higher energies and has a small blue shift by augment of temperature. (3) THG enhances and all of peaks have a red shift by increment of pressure. (4) THG has a minimum around z(0) = 4 nm in all magnetic field, temperature and pressure cases. Also, all of peaks have a blue shift by augment of z(0) until z(0) = 4 nm and then have a red shit by increasing the z(0).

16.Mobile malware attacks: Review, taxonomy & future directions

Author:Qamar, A;Karim, A;Chang, V

Source:FUTURE GENERATION COMPUTER SYSTEMS-THE INTERNATIONAL JOURNAL OF ESCIENCE,2019,Vol.97

Abstract:A pervasive increase in the adoption rate of smartphones with Android OS is noted in recent years. Android's popular and attractive environment not only captured the attention of users but also increased security concerns. As a result, Android malware detection is one of the sizzling topics in the mobile security domain. This paper provides a comprehensive review of state-of-the-art mobile malware attacks, vulnerabilities, detection techniques and security solutions over the period of 2013-2019 that majorly targeted Android platform. We have presented various well-organized and in-depth taxonomies that uncover mobile malware detection approaches based on their analysis techniques, working platform, data acquisition, operational impact, obtained results and artificial intelligence component involved. Another taxonomy comprises of mobile malware attack vector is presented to look threat clusters and loopholes to locate their malicious widespread impact on communities. Furthermore, we have discussed and classified forensic analysis efforts in mobile malware detection perspective. From the intruder point of view, we have compared various evasion techniques that are used prominently by the malware authors to hinder detection efforts. Finally, future work directions are presented as guidelines for academia and industry alike to help them reduce or even avoid the harmful impact of these annoying efforts. (C) 2019 Elsevier B.V. All rights reserved.

17.Mobile crowdsensing: A survey on privacy-preservation, task management, assignment models, and incentives mechanisms

Author:Khan, F;Rehman, AU;Zheng, JB;Jan, MA;Alam, M

Source:FUTURE GENERATION COMPUTER SYSTEMS-THE INTERNATIONAL JOURNAL OF ESCIENCE,2019,Vol.100

Abstract:Mobile crowdsensing is a useful technique to collect detailed information from mobile devices of the participants. The participants need to participate to sense and transmit valuable information to the servers. Due to the technological growth, various components of mobile devices such as accelerometer, gyroscope, camera and inertial, collect vast volumes of data in a quick, efficient, and cost-effective manner. However, a mobile crowdsensing paradigm may result in serious privacy and security breaches by exposing the mobile devices to various threats and vulnerabilities. This leakage of privacy has an adverse impact on the usage and participation of mobile devices. Motivated by these threats and privacy challenges, we investigate the current approaches used for preserving privacy in mobile crowdsensing applications. After a generic description of mobile crowdsensing systems and their components, we discuss critical issues related to privacy preservation, such as task management, task assignment models, and incentive mechanisms. We also discuss various mobile crowdsensing mechanisms available in the literature. Finally, we highlight numerous research challenges that need to be addressed to improve the performance of future privacy-preserving mechanisms for mobile crowdsensing applications. (C) 2019 Elsevier B.V. All rights reserved.

18.Structural diversity, surface composition, and redox behavior in the LA0.6SR0.4CoO3-PrO2-delta system

Author:Konysheva, Elena Yu. ; Bukaemskiy, Andrey A. ; Kuznetsov, Michail V. ; Ma, Tianzheng ; Ermolenko, Yurii E.

Source:Advances in Chemistry Research,2015,Vol.25

Abstract:Phase composition, crystal structure of components, surface composition, and redox behavior were explored in the (100-x) La0.6Sr0.4CoO3-xPrO2-δ (LSCPx) system under air. At high temperatures, a fraction of La0.6Sr0.4CoO3 perovskite phase interacts with praseodymium oxide, forming a new layered perovskite-like phase relating to the Ruddlesden-Popper family of An+1BnO3n+1 compounds with n=1. The Ruddlesden-Popper phase with K2NiF4-type structure (I4/mmm, no.139) exists in a wide compositional range. At room temperature the LSCPx (2 ≤ x ≤ 40) are two-phase compositions, comprising of the perovskite phase with rhombohedral distortion ( R3c, no. 167) and Ruddlesden-Popper phase. Evolution of lattice parameters for both perovskite and Ruddlesden-Popper phases with the raise in the Pr content was discussed. La0.93Sr0.62Pr0.45CoO4 compound with Ruddlesden-Popper structure was synthesized. Both single phase La0.93Sr0.62Pr0.45CoO4 and newly formed Ruddlesden-Popper phase in the two-phase LSCPx (2 ≤ x ≤ 40) exhibit similar behavior with the temperature variation (25-820oC) the expansion of the unit cell along the c-axis is noticeably stronger than within the a-b plain. X-ray photoelectron spectroscopy study indicates stronger accommodation of Sr cations within the Ruddlesden-Popper structure. Surface depletion in Co decreases in the two-phase LSCPx compositions with the raise in the fraction of the phase with the Ruddlesden-Popper structure, assuming that the presence of a second phase can facilitate the re-arrangement of cations between the volume and surface. The total oxygen exchange between the gas phase and the two-phase LSCPx (2 ≤ x ≤ 20) compositions decreases gradually with the increase in Pr content in the composites and it becomes almost negligible in the LSCPx (20 ≤ x ≤ 40). This result is unexpected and could be associated with the simultaneous involvement of Pr and Co cations in the redox process. © 2015 Nova Science Publishers, Inc.

19.Four supramolecular isomers of dichloridobis(1,10-phenanthroline)cobalt(II): synthesis, structure characterization and isomerization

Author:Chen, XC;Han, SM;Wang, RY;Li, Y

Source:ACTA CRYSTALLOGRAPHICA SECTION C-STRUCTURAL CHEMISTRY,2016,Vol.72

Abstract:Crystal engineering can be described as the understanding of intermolecular interactions in the context of crystal packing and the utilization of such understanding to design new solids with desired physical and chemical properties. Free-energy differences between supramolecular isomers are generally small and minor changes in the crystallization conditions may result in the occurrence of new isomers. The study of supramolecular isomerism will help us to understand the mechanism of crystallization, a very central concept of crystal engineering. Two supramolecular isomers of dichloridobis(1,10-phenanthroline-k(2) N, N') cobalt(II), [CoCl2(C12H8N2)(2)], i.e. (IA) (orthorhombic) and (IB) (monoclinic), and two supramolecular isomers of dichloridobis(1,10-phenanthroline-k(2) N, N') cobalt(II) N, N-dimethylformamide monosolvate, [CoCl2(C12H8N2)(2)]center dot C3H7NO, i.e. (IIA) (orthorhombic) and (IIB) (monoclinic), were synthesized in dimethylformamide (DMF) and structurally characterized. Of these, (IA) and (IIA) have been prepared and structurally characterized previously [Li et al. (2007). Acta Cryst. E63, m1880-m1880; Cai et al. (2008). Acta Cryst. E64, m1328-m1329]. We found that the heating rate is a key factor for the crystallization of (IA) or (IB), while the temperature difference is responsible for the crystallization of (IIA) or (IIB). Based on the crystallization conditions, isomerization behaviour, the KPI (Kitajgorodskij packing index) values and the density data, (IB) and (IIA) are assigned as the thermodynamic and stable kinetic isomers, respectively, while (IA) and (IIB) are assigned as the metastable kinetic products. The 1,10-phenanthroline (phen) ligands interact with each other through offset face-to-face (OFF) pi-pi stacking in (IB) and (IIB), but by edge-to-face (EF) C-H center dot center dot center dot pi interactions in (IA) and (IIA). Meanwhile, the DMF molecules in (IIB) connect to neighbouring [CoCl2(phen)(2)] units through two C-H center dot center dot center dot Cl hydrogen bonds, whereas there are no obvious interactions between DMF molecules and [CoCl2(phen)(2)] units in (IIA). Since OFF pi-pi stacking is generally stronger than EF C-H center dot center dot center dot pi interactions for transition-metal complexes with nitrogen-containing aromatic ligands, (IIA) is among the uncommon examples that are stable and densely packed but that do not following Etter's intermolecular interaction hierarchy.

20.Synthesis, structure and electrochemistry of ruthenium(II) and (III) mono-and bis-oxalato complexes

Author:Elnajjar, FO;Wang, RY;Aquino, MAS

Source:INORGANICA CHIMICA ACTA,2020,Vol.502

Abstract:Using trans- [NH2Me2][Ru(eta(2)-ox)(2)(H2O)(2)]center dot 4H(2)O 1 as starting material, as well as its original preparation as a guide, the synthesis of trans-[NH2Me2][Ru(eta(2)-ox)(2)(PPh3)(2)] 2, trans-[pyH] [Ru(eta(2)-ox)(2)(H2O)(2)]center dot 4H(2)O 3, trans-[PyH] [Ru(eta(2) -ox)(2)(py)(2)]center dot 2.5H(2)O 4, [Ru(eta(2)-ox)(py)(4)]center dot 4CHCl(3) 5 and fac-[Ru(eta(2)-ox)(DMSO-S)(3) (DMSO-O)]center dot 1.34H(2)O 6 are outlined. Complexes 2-6 have been characterized using elemental analysis, IR, UV-visible, H-1 NMR, and X-ray diffraction. In addition, their electrochemical behaviour has been analyzed using cyclic and Osteryoung square-wave voltammetries with complex 6 displaying linkage isomerization.
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